Pipelines for the transportation of fluids, such as natural gas, petroleum products or water, are often buried underground for a significant distance in a variety of terrains. Usually, a ditch is dug in the terrain, the pipeline laid in the ditch and the ditch and pipeline backfilled with the material dug out to form the ditch.
The pipeline is intended to remain buried for a significant period of time. This requirement can be a problem, particularly when traversing low lying areas subject to inundation by water, such as muskeg terrain. The buoyancy effect produced by the fluid medium encompassing the pipeline in such areas tends to shift the position of the pipeline towards the surface with the potential for the pipeline to eventually break through the surface. For this reason, concrete weights of various designs have been traditionally placed at intervals along the ditch to resist the buoyancy force on the pipeline caused by the water or other encompassing fluid medium and to maintain the pipeline in a buried condition.
These concrete weights are expensive to manufacture and transport to the often remote locations of use. However, they are employed in the absence of a viable alternative. The present invention is directed towards providing such an alternative.
The applicants are aware of a variety of prior patents relating to pipeline anchoring arrangements, some to maintain the pipeline submerged in an aqueous environment, such as a seabed, and some to maintain the pipeline buried in-ground, as follows:
U.S. Pat. Nos. 687,389, 4,166,710, USSR 1,041,789, U.S. Pat. Nos. 3,675,432, 4,242,010, USSR 1,092,322, U.S. Pat. Nos. 3,793,845, 4,338,045, USSR 1,268,860, U.S. Pat. Nos. 3,903,704, 4,477,206, USSR 1,314,177, U.S. Pat. No. 4,126,012. None of this prior art described or suggests the relatively simple form of weighting device provided herein.